By now, you have probably heard that Portugal won the 2016 Euro-Cup and they did so without their star player and captain Cristiano Ronaldo. While limited news has been released regarding the status of his injury, I came across an ESPN article classifying it as a “ligament strain” (I will forgive them for the misuse of the word strain in this case). What was more interesting, was the following line: “Real Madrid’s Cristiano Ronaldo has visited a clinic while on holiday in Ibiza for hyperbaric oxygen therapy (HBO) to speed recovery from his current knee injury”.

So what is HBO and what’s the evidence surrounding it?

HBO is a medical treatment in which the patient is breathing 100% oxygen intermittently at a pressure greater than one atmosphere (ATA).

How does it work?

In short, the body carries oxygen in two ways:

Attached to haemoglobin

Dissolved in the plasma

Oxygen is normally entirely bound to Haemoglobin at our current atmospheric pressure (1ATA). However, at 100% oxygen (2 or 3 ATA), a significant portion of oxygen is now dissolved into the plasma.

HBO is thought to reverse tissue hypoxia, enhance phagocytosis (removal of dead or damaged cells) and stimulate angiogenesis (the growth of new blood vessels) to the damaged area- in turn, increasing blood flow and rate of healing.

Who is it for?

Currently, there is limited research regarding HBO and its effect on soft tissue and more specifically ligament injuries. The majority of research focuses on its positive influence for more severe and stubborn conditions including osteomyelitis, diabetic foot ulcers, non-union fractures, compromised grafts and severe soft tissue infections. Furthermore, the public may be more familiar with HBO to treat decompression sickness in diving accidents.

How is it administered?

HBO is administered in two ways:

Monoplace chambers- where there is only enough room for one person

Multiplace chambers- where there is room for multiple people including the patient as well as a support personnel. This method is preferred, as you will read below there are some risks associated with HBO in which emergent medical attention is required.

The chamber is then pressurized with compressed air while the patient breathes oxygen via a mask or head tent.

Risks

According to studies, HBO is generally safe and well tolerated. Mild to moderate side effects include middle ear barotraumas, sinus squeezing, claustrophobia and anxiety. More severe complications include seizures and pulmonary edema requiring immediate attention.

The following are contraindications to HBO: pneumothorax, high fever, seizure history, emphysema and upper respiratory tract infections.

Conclusion

From the quick scan of the literature, most papers conclude that HBO is a safe and effective treatment with a low complication risk. However, studies are limited and there is a need for better clinical research and controlled trials. In conclusion, HBO should be used in conjunction with aggressive, multidisciplinary treatment protocols and not used as a substitute treatment.